It is known to locate a subwoofer enclosure for a vehicle sound systems beneath one of the vehicle seats. In these prior systems, the subwoofer enclosure is separate from the load bearing support frame or other support structure of the vehicle seat. This leads to a suboptimal arrangement in which the volume of the subwoofer enclosure is not optimized or maximized with respect to the volume available under the vehicle seat and/or the space under only a single seat is used when additional empty space is available for use under an adjacent seat. Also, the subwoofer speaker, itself, is often not optimally located relative to the seat, the floor, and other surrounding structures of the vehicle. Also, prior systems do not allow the structure of the subwoofer enclosure to be used to increase the safety of the occupant of the seat under which the subwoofer enclosure is located.